In his first-ever interview, the sole Australian survivor of the Waco siege has revealed to 60 Minutes what really took place during the 51-day stand-off, and why he believes crazed cult leader David Koresh will one day return to Earth as the son of God.

He was sentenced on Monday by Supreme Court Justice Paul Coghlan to 20 years in prison, with a non-parole period of 16 years, and his term of imprisonment was backdated by 433 days for time already served.